llvm/lib/DebugInfo/DWARF/DWARFDebugAbbrev.cpp

   1 //===- DWARFDebugAbbrev.cpp -----------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "llvm/DebugInfo/DWARF/DWARFDebugAbbrev.h"
  10 #include "llvm/Support/Format.h"
  11 #include "llvm/Support/raw_ostream.h"
  12 #include <algorithm>
  13 #include <cinttypes>
  14 #include <cstdint>
  15
  16 using namespace llvm;
  17
  18 DWARFAbbreviationDeclarationSet::DWARFAbbreviationDeclarationSet() {
  19   clear();
  20 }
  21
  22 void DWARFAbbreviationDeclarationSet::clear() {
  23   Offset = 0;
  24   FirstAbbrCode = 0;
  25   Decls.clear();
  26 }
  27
  28 bool DWARFAbbreviationDeclarationSet::extract(DataExtractor Data,
  29                                               uint64_t *OffsetPtr) {
  30   clear();
  31   const uint64_t BeginOffset = *OffsetPtr;
  32   Offset = BeginOffset;
  33   DWARFAbbreviationDeclaration AbbrDecl;
  34   uint32_t PrevAbbrCode = 0;
  35   while (AbbrDecl.extract(Data, OffsetPtr)) {
  36     if (FirstAbbrCode == 0) {
  37       FirstAbbrCode = AbbrDecl.getCode();
  38     } else {
  39       if (PrevAbbrCode + 1 != AbbrDecl.getCode()) {
  40         // Codes are not consecutive, can't do O(1) lookups.
  41         FirstAbbrCode = UINT32_MAX;
  42       }
  43     }
  44     PrevAbbrCode = AbbrDecl.getCode();
  45     Decls.push_back(std::move(AbbrDecl));
  46   }
  47   return BeginOffset != *OffsetPtr;
  48 }
  49
  50 void DWARFAbbreviationDeclarationSet::dump(raw_ostream &OS) const {
  51   for (const auto &Decl : Decls)
  52     Decl.dump(OS);
  53 }
  54
  55 const DWARFAbbreviationDeclaration *
  56 DWARFAbbreviationDeclarationSet::getAbbreviationDeclaration(
  57     uint32_t AbbrCode) const {
  58   if (FirstAbbrCode == UINT32_MAX) {
  59     for (const auto &Decl : Decls) {
  60       if (Decl.getCode() == AbbrCode)
  61         return &Decl;
  62     }
  63     return nullptr;
  64   }
  65   if (AbbrCode < FirstAbbrCode || AbbrCode >= FirstAbbrCode + Decls.size())
  66     return nullptr;
  67   return &Decls[AbbrCode - FirstAbbrCode];
  68 }
  69
  70 std::string DWARFAbbreviationDeclarationSet::getCodeRange() const {
  71   // Create a sorted list of all abbrev codes.
  72   std::vector<uint32_t> Codes;
  73   Codes.reserve(Decls.size());
  74   for (const auto &Decl : Decls)
  75     Codes.push_back(Decl.getCode());
  76
  77   std::string Buffer = "";
  78   raw_string_ostream Stream(Buffer);
  79   // Each iteration through this loop represents a single contiguous range in
  80   // the set of codes.
  81   for (auto Current = Codes.begin(), End = Codes.end(); Current != End;) {
  82     uint32_t RangeStart = *Current;
  83     // Add the current range start.
  84     Stream << *Current;
  85     uint32_t RangeEnd = RangeStart;
  86     // Find the end of the current range.
  87     while (++Current != End && *Current == RangeEnd + 1)
  88       ++RangeEnd;
  89     // If there is more than one value in the range, add the range end too.
  90     if (RangeStart != RangeEnd)
  91       Stream << "-" << RangeEnd;
  92     // If there is at least one more range, add a separator.
  93     if (Current != End)
  94       Stream << ", ";
  95   }
  96   return Buffer;
  97 }
  98
  99 DWARFDebugAbbrev::DWARFDebugAbbrev() { clear(); }
 100
 101 void DWARFDebugAbbrev::clear() {
 102   AbbrDeclSets.clear();
 103   PrevAbbrOffsetPos = AbbrDeclSets.end();
 104 }
 105
 106 void DWARFDebugAbbrev::extract(DataExtractor Data) {
 107   clear();
 108   this->Data = Data;
 109 }
 110
 111 void DWARFDebugAbbrev::parse() const {
 112   if (!Data)
 113     return;
 114   uint64_t Offset = 0;
 115   auto I = AbbrDeclSets.begin();
 116   while (Data->isValidOffset(Offset)) {
 117     while (I != AbbrDeclSets.end() && I->first < Offset)
 118       ++I;
 119     uint64_t CUAbbrOffset = Offset;
 120     DWARFAbbreviationDeclarationSet AbbrDecls;
 121     if (!AbbrDecls.extract(*Data, &Offset))
 122       break;
 123     AbbrDeclSets.insert(I, std::make_pair(CUAbbrOffset, std::move(AbbrDecls)));
 124   }
 125   Data = None;
 126 }
 127
 128 void DWARFDebugAbbrev::dump(raw_ostream &OS) const {
 129   parse();
 130
 131   if (AbbrDeclSets.empty()) {
 132     OS << "< EMPTY >\n";
 133     return;
 134   }
 135
 136   for (const auto &I : AbbrDeclSets) {
 137     OS << format("Abbrev table for offset: 0x%8.8" PRIx64 "\n", I.first);
 138     I.second.dump(OS);
 139   }
 140 }
 141
 142 const DWARFAbbreviationDeclarationSet*
 143 DWARFDebugAbbrev::getAbbreviationDeclarationSet(uint64_t CUAbbrOffset) const {
 144   const auto End = AbbrDeclSets.end();
 145   if (PrevAbbrOffsetPos != End && PrevAbbrOffsetPos->first == CUAbbrOffset) {
 146     return &(PrevAbbrOffsetPos->second);
 147   }
 148
 149   const auto Pos = AbbrDeclSets.find(CUAbbrOffset);
 150   if (Pos != End) {
 151     PrevAbbrOffsetPos = Pos;
 152     return &(Pos->second);
 153   }
 154
 155   if (Data && CUAbbrOffset < Data->getData().size()) {
 156     uint64_t Offset = CUAbbrOffset;
 157     DWARFAbbreviationDeclarationSet AbbrDecls;
 158     if (!AbbrDecls.extract(*Data, &Offset))
 159       return nullptr;
 160     PrevAbbrOffsetPos =
 161         AbbrDeclSets.insert(std::make_pair(CUAbbrOffset, std::move(AbbrDecls)))
 162             .first;
 163     return &PrevAbbrOffsetPos->second;
 164   }
 165
 166   return nullptr;
 167 }